The present invention relates to a household appliance, for example a dishwasher, and a controlling method for such a household appliance.
A dishwasher has a circulation pump for recirculating dishwashing liquid in the washing compartment of the dishwasher and a drain pump for emptying soiled dishwashing liquid from the washing compartment. Technically important aspects of the pumps used are that they are quiet in operation and extremely efficient.
The drain pump, which can also be called a discharge pump, is connected to a pump well on the intake side. The drain pump also has a chamber in which a pump wheel operates. In an upper region, the pump chamber is connected with the pump well via a ventilation opening. In this way, any gas collecting above a column of residual liquid after the pump wheel has been switched off can escape via the ventilation opening in the pump well so that the drain pump is ventilated. As a result, the pump wheel plunges deeper into the residual dishwashing liquid. Then, when it is switched on again, the drain pump attains maximum efficiency in a relatively short time and while operating quietly.
A water conducting appliance with a pump and a possibility of ventilating this pump is described in DE 10 2009 002 224 A1. The pump in the household appliance can convey liquid in a normal operating mode. In addition, the pump can be ventilated using a ventilation operating mode that can be activated before the normal operating mode, during which at least part of a gas bubble can be conveyed against the direction of conveyance and in normal operating mode, from a pump chamber of the pump to an inlet for liquids of the pump.